Vibrio spp

Gram Stain

• Gram negative bacilli - fermenter straight, curved or comma shaped (facultative anaerobic)

Clinical Significance

These organisms are found in water sources (fresh water/saltwater) and in food sources.

Infections (intestinal and extraintestinal) result from ingestion or contact with contaminated water. Intestinal infections range from mild to severe and are typically self-limited. Extraintestinal infections include septicemia, wound, soft tissue infections, conjunctivitis, and otitis externa.

V. alginolyticus - associated with conjunctivitis, gastroenteritis, bacteremia, necrotizing fasciitis.

V. cadiariae - associated with shark bites.

V. cincinnatiensis - associated with bacteremia and meningitis.

V. damsela (renamed Photobacterium damsel) - associated with wound infections following salt water exposure.

V. fluvialis - associated  with gastroenteritis.

V. furnisii - associated with gastroenteritis related to food poisoning.

V. hollisae - associated with gastroenteritis after ingestion of raw seafood.

V. metschnikovii - causes fowl cholera but has been associated with human infections including septicemia, peritonitis, wound and urinary tract infections.

V. mimicus - associated with diarrheal syndrome and swimmer’s ear

V. parahaemolyticus - associated with gastroenteritis following ingestion of raw seafood or exposure to contaminated water.

V. vulnificus - associated with life-threatening infection, septicemia, especially in patients with pre-existing liver disease.  Also associated with wound infections which may progress to bullous cellulitis and muscle necrosis, following fish handling, contaminated water, or infected marine animals.

Usual Susceptibility Pattern

These organisms are typically susceptible to tetracyclines, aminoglycosides, quinolones, 3rd generation cephalosporins, and carbapenems.

Susceptibility to TMP/SMX is variable.

Ampicillin is not effective in vivo despite often testing susceptible in vitro.

Narrow spectrum cephalosporins do not have reliable activity.

Combination therapy (ceftriaxone + doxycycline) is recommended for severe V. vulnificus infections.